Spierer, a sophomore at Indiana from Greenburgh, N.Y., disappeared two years ago in Bloomington, Ind., after a night of partying with friends and acquaintances.

Robert and Charlene Spierer claim in a lawsuit that their daughter's last known interaction with Corey Rossman, Mike Beth and Jay Rosenbaum is to blame.

Her interaction with the three former students ultimately resulted in the 20-year-old's "disappearance, death or injury," according to attorney Jason Barclay.

The complaint says the men's negligence led to the disappearance of Lauren Spierer, which remains unsolved, according to state and local police.

The lawsuit was filed last month in Monroe County, Ind. The complaint seeks a jury trial against the men, who are no longer students, and monetary damages.

The family's attorney said it was not a decision they made lightly, or one made with the presumption of anything more than the documents imply.

"Rob and Charlene Spierer authorized the filing of this lawsuit with great reluctance and only after we counseled them that they would lose certain legal rights if not exercised by the two-year anniversary of Lauren’s disappearance," Barclay said in a statement.

"We hope no one will misinterpret this action. Any parent in search of information about a missing child would use every resource available to them," he added.

"Therefore, we intend to use the rights afforded by the civil justice system to obtain answers to questions that have gone unanswered for too long."

"We fully expect that those with relevant information will cooperate with this process."

Fox News interviewed the Spierers last month in an interview during which they expressed doubts the men were telling the truth about their daughter's last hours.

Robert Spierer, for his part, specifically said he is not convinced Lauren ever left the men's apartment building, which was her last known stop that night.